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linux/arch/sh/kernel/vmlinux.lds.S
Tejun Heo 0415b00d17 percpu: Always align percpu output section to PAGE_SIZE
Percpu allocator honors alignment request upto PAGE_SIZE and both the
percpu addresses in the percpu address space and the translated kernel
addresses should be aligned accordingly.  The calculation of the
former depends on the alignment of percpu output section in the kernel
image.

The linker script macros PERCPU_VADDR() and PERCPU() are used to
define this output section and the latter takes @align parameter.
Several architectures are using @align smaller than PAGE_SIZE breaking
percpu memory alignment.

This patch removes @align parameter from PERCPU(), renames it to
PERCPU_SECTION() and makes it always align to PAGE_SIZE.  While at it,
add PCPU_SETUP_BUG_ON() checks such that alignment problems are
reliably detected and remove percpu alignment comment recently added
in workqueue.c as the condition would trigger BUG way before reaching
there.

For um, this patch raises the alignment of percpu area.  As the area
is in .init, there shouldn't be any noticeable difference.

This problem was discovered by David Howells while debugging boot
failure on mn10300.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Cc: uclinux-dist-devel@blackfin.uclinux.org
Cc: David Howells <dhowells@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: user-mode-linux-devel@lists.sourceforge.net
2011-03-24 18:50:09 +01:00

89 lines
1.6 KiB
ArmAsm

/*
* ld script to make SuperH Linux kernel
* Written by Niibe Yutaka and Paul Mundt
*/
#ifdef CONFIG_SUPERH64
#define LOAD_OFFSET PAGE_OFFSET
OUTPUT_ARCH(sh:sh5)
#else
#define LOAD_OFFSET 0
OUTPUT_ARCH(sh)
#endif
#include <asm/thread_info.h>
#include <asm/cache.h>
#include <asm/vmlinux.lds.h>
#ifdef CONFIG_PMB
#define MEMORY_OFFSET 0
#else
#define MEMORY_OFFSET __MEMORY_START
#endif
ENTRY(_start)
SECTIONS
{
. = PAGE_OFFSET + MEMORY_OFFSET + CONFIG_ZERO_PAGE_OFFSET;
_text = .; /* Text and read-only data */
.empty_zero_page : AT(ADDR(.empty_zero_page) - LOAD_OFFSET) {
*(.empty_zero_page)
} = 0
.text : AT(ADDR(.text) - LOAD_OFFSET) {
HEAD_TEXT
TEXT_TEXT
EXTRA_TEXT
SCHED_TEXT
LOCK_TEXT
KPROBES_TEXT
IRQENTRY_TEXT
*(.fixup)
*(.gnu.warning)
_etext = .; /* End of text section */
} = 0x0009
EXCEPTION_TABLE(16)
NOTES
_sdata = .;
RO_DATA(PAGE_SIZE)
RW_DATA_SECTION(L1_CACHE_BYTES, PAGE_SIZE, THREAD_SIZE)
_edata = .;
DWARF_EH_FRAME
. = ALIGN(PAGE_SIZE); /* Init code and data */
__init_begin = .;
INIT_TEXT_SECTION(PAGE_SIZE)
INIT_DATA_SECTION(16)
. = ALIGN(4);
.machvec.init : AT(ADDR(.machvec.init) - LOAD_OFFSET) {
__machvec_start = .;
*(.machvec.init)
__machvec_end = .;
}
PERCPU_SECTION(L1_CACHE_BYTES)
/*
* .exit.text is discarded at runtime, not link time, to deal with
* references from __bug_table
*/
.exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) { EXIT_TEXT }
.exit.data : AT(ADDR(.exit.data) - LOAD_OFFSET) { EXIT_DATA }
. = ALIGN(PAGE_SIZE);
__init_end = .;
BSS_SECTION(0, PAGE_SIZE, 4)
_ebss = .; /* uClinux MTD sucks */
_end = . ;
STABS_DEBUG
DWARF_DEBUG
DISCARDS
}